This document defines key terms related to multilingualism such as vitality, diglossia, code switching, and code mixing. Vitality refers to the status and use of a language within a speech community. Diglossia describes a situation where two varieties of the same language are used for different purposes. Code switching involves alternating between two or more languages or language varieties based on the social context or situation, while code mixing blends elements of different languages together.

2. Multilingualism

3. Key Terms
Vitality
Diglossia
High variety
Low variety
Code switching
Domain
Situational
Passive
knowledge
Active knowledge
Code mixing
Speech levels

4. Vitality

8. Code switching
The social and physical
setting in which speakers find
themselves.
A more idiosyncratic and
personalized view of the context or
situation of language use. In this
text, used to describe one of the
motivations for code switching

9. The ability to
understand,
but not
speak, a
language.
Knowledge of
a linguistic
variety that
includes the
ability to
produce and
use that
variety, and not
only
understand it.

10. Code mixing